BSI-551 / Biosion - LARVOL DELTA

A novel PD-1xVEGFxCTLA-4 tri-specific antibody, BSI-551, demonstrates potent efficacy and favorable safety in preclinical tumor models (AACR 2026) - "Here, we report the development and preclinical activity of this new therapeutic. BSI-551 was generated based on the sequences of in-house PD-1 antibody BSI-050, anti-VEGF antibody ranibizumab, and anti-CTLA-4 antibody tremelimumab...In a CRC cancer model (HT-29), treatment with BSI-551 resulted in a significant tumor regression and better tumor growth inhibition (TGI) as compared to combo treatment of pembrolizumab, ipilimumab and bevacizumab. In conclusion, BSI-551 demonstrates significant potential as a next-generation I/O therapy designed to be effective in tumors with poor responses to current monotherapies. Further pharmacokinetics, toxicity, and IND-enabling studies of BSI-551 are underway."

IO biomarker • Preclinical • Trispecific • Oncology • CD4 • CD8 • CD80 • FAT4 • IL2